In current wireless communication, if a sender of an Evolved Universal Terrestrial Radio Access Network Node B (E-UTRAN NodeB, abbreviated as eNodeB or eNB) adopts multiple antennae, a spatial multiplexing manner may be adopted to increase a transmission rate, that is, different data is sent at different antenna positions on the same time-frequency resource of the sender, and a receiver (i.e. User Equipment (UE)) may also adopt multiple antennae. Under a normal condition, Multiple Input Multiple Output (MIMO) may have two transmission forms. One transmission form is Single User-MIMO (SU-MIMO) by which all antenna resources are allocated to the same user under an SU condition; while the other transmission form is Multi User-MIMO (MU-MIMO) by which resources of different antenna spaces are allocated to different users under an MU condition and services are provided for multiple users at the same time and on the same carrier by virtue of space division, and by the MU-MIMO transmission form, average throughput of a cell can be effectively improved.
Specifically, SU-MIMO refers to that one user terminal exclusively occupies a physical resource allocated to the user terminal within one transmission interval. MU-MIMO refers to that one user terminal and at least one other user terminal share a physical resource allocated to the user terminal within one transmission interval. A user terminal and other user terminals may share the same physical resource (which may include: a time-frequency resource) in a space division multiple access or space division multiplexing manner.
A network of 3rd Generation Partnership Project (3GPP) Release 8/Release 9/Release 10 (R8/R9/R10) and a subsequent version adopts a flat network architecture. FIG. 1 is a diagram showing a network architecture based on Long Term Evolution (LTE) and subsequent evolution standards according to a related technology. As shown in FIG. 1, eNBs are main bodies of a wireless network, and the entire access network is completely formed by the eNBs, wherein the eNBs may have logic or physical connections between each other according to a requirement, and the eNBs adopt an Internet Protocol (IP) for bottom-layer transmission, and are logically interconnected through X2 interfaces. Such a design manner is mainly used for supporting mobility of UE in the entire network to ensure seamless handover of a user. In addition, the X2 interfaces are also responsible for load bearing and interference management. Each eNB is connected to a System Architecture Evolution (SAE) core network, i.e. an Evolved Packet Core (EPC) network, through an S1 interface.
A series of LTE standards R8/R9/R10 define a UE specific reference signal. The UE specific reference signal is mainly configured for transmission modes 7, 8 and 9, and the UE specific reference signal is embedded only in the resources to which the high-speed Physical Downlink Shared Channel (PDSCH) is mapped for the UEs. A UE specific reference signal may be used to derive the channel estimation for demodulating the data in the corresponding PDSCH resource blocks (RBs). Therefore, a UE specific reference signal is considered to adopt an independent antenna port, and has a specific channel response from an eNB to UE. Such a UE specific reference signal carries UE information, and is sent only on a frequency band occupied by data of UE, therefore it is unnecessary to cover an Orthogonal Frequency Division Multiplexing (OFDM) symbol occupied by a control channel on the time domain.
A typical usage of the UE specific reference signals is to enable beamforming of the data transmissions to specific UEs. For example: a Cell Reference Signal (CRS) is not transmitted through an independent physical antenna, and an eNB may generate a narrow beam in a specific UE direction by virtue of a correlation matrix of a physical antenna unit. Such a beam has a specific signal response between the eNB and the UE, and it is necessary to perform coherent demodulation on beam data by virtue of a UE specific reference signal. Actually, a channel response carried by a UE specific reference signal may be directly understood as a channel matrix combined with a precoding weight.
In standard LTE R8, an Inter-Cell Interference Coordination (ICIC) method is introduced to avoid inter-cell interference. By using such a method, an eNB may calculate Relative Narrowband TX Power (RNTP) to judge whether the interference brought by a certain Physical Resource Block (PRB) exceeds a preset threshold or not. If the interference brought by the PRB exceeds the preset threshold, an adjacent point is notified, through interaction signalling between point, that the corresponding PRB generates serious interference to the adjacent point may be generated through interaction signalling between points; and if the interference brought by the PRB does not exceed the preset threshold, the adjacent point is notified, through the interaction signalling between the points, that the corresponding PRB does not generate relatively serious interference to the adjacent point. RNTP is a value relative to rated output power of the eNB, and therefore is required to be normalized to output power of the eNB. RNTP is exchanged between adjacent eNBs through an X2 interface message. RNTP is an indicator of a proactive downlink ICIC manner. The 3GPP defines RNTP related information by adopting an Information Element (IE) in an X2 application protocol, wherein the RNTP related information may include fields such as RNTP per PRB Bitmap, RNTP threshold, Number of Cell Specific Antenna Ports, P_B and Physical Downlink Control Channel (PDCCH) Interference Impact.
In mobile communication, capacity and data rate of a network may be increased in a specific area by utilizing an irregular network deployment, namely by employing a low-power Pico point as compensation of a Macro point, and such an irregular network belongs to a heterogeneous network. However, simultaneous adoption of the same frequency in different layers will result in serious interlayer interference. In LTE R10 and R11, a concept of Almost Blank Subframe (ABS) is introduced, which is a time-domain ICIC technology, and a main purpose of introducing the ABS is to reduce interference of a Macro point to a terminal of a Pico point in such a manner that the Macro point does not send data or sends the data under low power on the ABS, thereby reducing interference of downlink transmission of the Macro point to an edge terminal of the Pico point. The 3GPP regulates to define ABS related information by adopting an IE in the X2 application protocol, and the ABS related information is exchanged between adjacent eNBs through an X2 interface message, wherein the ABS related information may include fields such as ABS pattern Information Bitmap, Number of Cell Specific Antenna Ports, Measurement Subset Bitmap and ABS inactive.
A coordinated MIMO technology, also called a Coordinated Multiple Point Transmission and Reception (COMP) technology, improves capacity and transmission reliability of wireless links on edges of cells by virtue of coordinated transmission from sending antennae of multiple cells, and may effectively solve the problem of cell edge interference. An important factor which limits system throughput performance of a cellular network is inter-cell interference, particularly for a cell edge user. COMP can coordinate scheduling and transmission of different cells, effectively deal with interference from an adjacent cell and remarkably enhance a data rate of a cell edge user. In order to implement COMP, communication between adjacent cells is required. If adjacent cells are managed by the same eNB, the implementation of COMP does not require standard signalling. However, in adjacent cells controlled by different eNBs, standard signalling is quite important, especially for a multi-manufacturer network. A COMP solution for an ideal backhaul condition is introduced in LTE R11, and a COMP solution for a non-ideal backhaul condition will be researched in future R12.
In the related technology, a conventional (time-domain or frequency-domain) ICIC technology may effectively reduce inter-cell interference, a COMP technology for an ideal backhaul condition may also reduce inter-cell interference, but there is no technical solution simultaneously supporting integration of the conventional ICIC technology and the COMP technology under a non-ideal backhaul condition in a present standard protocol and the related technology.